This invention relates to dental posts, and more particularly to a helically grooved dental post which includes a longitudinal contour to improve its retention within a prepared tooth stub on which a dental restoration will be erected.
In restoring dentition, one procedure is to build up a dental prosthetic structure onto a tooth stub. The tooth stub is initially prepared by cutting it down to provide a suitable support on which the prosthetic structure will be built. A bore is formed into the tooth stub in which a dental post is inserted. The dental post includes grooves thereabout for improving its retention in the bore formed in the tooth stub. Suitable dental cement is used for the retention. A portion of the dental post extends upwardly above the surface of the tooth stub so that as the dental prosthetic structure is formed or built up onto the tooth stub, it is retained in place on the tooth stub by means of the extending portion of the dental post.
Various types of grooves have been suggested in the prior art in order to improve the retention of the dental post within the cement prepared bore in the tooth stub. By way of example, there has been suggested to provide a helical thread about the periphery of the dental post. The inclusion of a longitudinal vent along the helical grooves permits escape of the air during insertion of the post and reduces the hydraulic pressure upon insertion. U.S. Pat. No. 4,268,253 describes a dental post having deep concave channels helically formed about the post to give the post a polygonal cross section. The use of helical flutes has been suggested in U.S. Pat. No. 4,479,783 assigned to the assignee of the present invention. Such helical flutes can be provided in a sequence with designated flutes being deeper than alternating shallower flutes. The use of such flutes can eliminate the need of the axial vent. Improvements in the retention capabilities of dental posts are also described in U.S. Pat. No. 4,571,187 assigned to the assignee of the present invention including an angled tang at the upper end of the post with projecting angular ribs about the tang to improve dental retention.
While the aforementioned dental posts have provided improvements with respect to the retention of the post in the bore, still further improvements in such retention would be beneficial. Additionally, the use of the helical grooves, flutes, and channels also provide a situation where the pin can bend or break along such indentations. Also, the grooves provide the possibility of shearing along length of the post.